Perhaps you should try some spelling variations:
khanh thai » nhanh thai, khanh thanh, khanh thuan
van khanh » van thanh, van hanh, van anh
cau tren » cu tren, dau tren, ca tren
vien cac » vien bach, vien dai, vien da
thai cau » thai cao, toan cau, thai van
xuc van » duc van, luc van, vuc van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
co hoi » co hoc, co loi
ve cac » va cac
o hai » co hai, so hai, o lai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((co hoi) or (o hai)). hieu ((ve cac) or (vien cac)) xuc van khanh thai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((co hoi) OR (o hai)). hieu ((ve cac) OR (vien cac)) xuc van khanh thai cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((co hoi) or (o hai)). hieu ((ve cac) or (vien cac)) xuc van khanh thai cau tren*.